Carrier for records



Oct. 29, 1935. c. J. DIPPEL 2,019,215

CARRIER FOR RECORDS Filed Sept. 28, 1954 Patented Oct. 29, 1935 PATENT OFFICE CARRIER FOR RECORDS Cornelis Johannes Dippel, Eindhoven, Netherlands, assignor to N. V. Philips Gloeilampenfabrieken, Eindhoven, Netherlands Application September 28, 1934, Serial No. 146,010 In Germany October 5,1933

9 Claims. (Cl. 274-43) My invention relates to carriers of records, and

more particularly to carriers for the mechanical copied. An apparatus of this type is described in U. S. Patent 1,919,116 to James A. Miller.

However, it should be well understood that my invention is not limited to the example given for its illustration, but applies broadly to mechanically recorded and optically reproducible vibration tracks.

The quality of such mechanically recorded and optically reproducible tracks, as will also be more fully explained hereafter, depends largely on the material of the layer 'in which the track is recorded. The best results have been obtained so far with layers formed of gelatin. This material has better cutting properties and is therefore better adapted for such mechanical recording, than celluloid or other similar materials also used for this purpose.

However, even when using gelatin as the material for the recording layer, serious difliculties exist, and the object of my invention is to eliminate or at least greatly reduce such difliculties.

One of the difiiculties is due to the comparatively rapid impairing of the cutting edge of the cutting tool, for instance, of the chisel, which brings about a number of serious difficulties.

First, due to such rapid damaging of the cutting edge of the tool, the tool has to be frequently sharpened and replaced, which not only increases the tool cost, but as the tool may have to be changed several times during a single recording, causes inconvenient and costly interruptions during the recording.

Even more important is the fact that the deterioration of the cutting edge brings about a corresponding impairing of the quality of the record, so that successive portions of a record, out without changing the tool. exhibit gradually poorer and poorer quality. The deterioration of the cutting edge of the tool manifestsitself by scratches appearing on the v bration track, which means of photocells and/or are photographically' scratches run in the direction of the movement of the carrier relatively to the cutting tool. With increased use of the tool the cutting edge becomes increasingly irregular and the number of scratches correspondingly increases, which re- 6 sults in an increasing distortion of the modulated borderline of the track.

The rate at which the number of scratches increases can be regarded as a measure of the wear on the cutting edge of the tool.

Thereby an increasing number of scratches correspondingly reduces the quality of reproduction from the record.

A further difficulty arises because of the fact, that, when cutting gelatin even with a newly and 15 as well as possible sharpened tool, the surface of the vibration track is more or less rough, instead of being smooth. This coarse or rough surface, which appears to the eye as if it were frosted, is not homogeneously transparent, but difluses 20 the light passing through same.

, The ,roughness of the cut track-surface seems to be due to the adhesiveness or stickiness exhibited by the gelatin in the state in which it is used for recording. This adhesiveness prevents the cutting tool from removing the material in a continuous smooth cut. In fact the removal of the material takes place in the form of intermittent chips, i. e., as a sequence of short individual cuts, which results in short, curled, and easily breakable cuttings, instead of in one smooth-continuous cutting.

As is well known from regular metal working practice, such intermittent cutting process requires much greater power than does smooth continuous' cutting. Such increase in required power causes, in recording, a considerable heating up of the cutting edge of the tool, which further accelerates the deterioration of the cutting edge and also otherwise deleteriously influences the cutting process.

Furthermore, the coarse or frosted-condition of the vibration track decreases the translucency of the track and also results in a track, the light 45 transparency of which is not homogeneous. In reproduction, the reduced translucency decreases the contrast efiect, and the lack of uniformity in translucency of the-track causes disturbing background noises, which are especially bother-.- some for the vibrations of small amplitudes.

I have found that all of the above drawbacks can be greatly reduced and practically eliminated by increasing the cutting properties of the gelatin used, 1. e., such qualities of these materials 5 which result in their ofiering less resistance to the cutting tool, avoid their tool, etc.

I have found, that considerable improvement in the cutting properties can be obtained by an addition of a sulfonated castor oil to the gelatin. Preferably, I add a sulfonated castor oil, known in trade under the trade mark Turkonol a substance, the chemical composition of which is not well known, but which is supposed to be a by polymerization originated diricindisulfoacid. (In regard to such substances see Enzyclopadie der Technischen Chemie, 9th volume, page 801, etc.)

The treatment of the gelatin with a substance of the character indicated (and hereafter referred to as the added substance) can take place by wholly or partly impregnating the gelatin with theadded substance after the gelatin has been given its final shape as a cutting layer on a carrier. Thereby, care is to be taken that the added substance penetrates sufficiently deep into the gelatin layer to cause the desired improvement of its cutting properties.

According to another process, a given percentage of the added substance is mixed with the gelatin before the latter is made into a carrier.

Especially good results are found with a material obtained in the following manner: 'Anaqueous solution of gelatin is first prepared by dissolving 6 to 10% by weight of gelatin in by weight of water, at a temperature not exceeding 55 C. Thereafter I add to 100 grams of dry gelatin, a quantity of at least 4 cubic centimeters, but preferably about 20 cubic centimeters, of a sulfonated castor oil, preferably Tiirkonol. The exact proportions of the mixture used may vary and depend on various factors, for instance on the type of gelatin used, the process and machinery used for mixing, etc. r

While an important application of my invention is in connection with mechanically recorded tracks which are reproduced by means of photoelectric cells or used as masters from which copies are made, my invention is not limited to such application. Also, while usually the carrier of the record forms a film, other types of carriers, for instance discs, cylinders, etc., may be used.

In order that the invention may be clearly understood and readily carried into effect, it will now be described more fully with reference to the accompanying drawing, in which:

Figure 1 is an enlarged top view of a film poradhesion to the tion carrying a mechanically recorded vibration track, which can be reproduced by means of light passing through same and illustrates the advantages obtained with my invention.

Fig. 2.is a cross section through the film, also showing the cutting tool while cutting the track.

The carrier shown in the drawing consists of three superimposed layers. The base or supporting layer I is made of a suitable transparent material, for instance of celluloid. The second layer 2 is also of transparent material. The material of this layer is in this case gelatin, this being the layer into which the track is cut and with which my invention is primarily concerned. The top layer 3 is the covering layer andis a comparatively thin opaque layer applied to layer 2.

The tool used for the recording is shown as a chisel M, having two cutting edges 4-4, which enclose with each other an angle 20:. By using a chisel in which the angle a i. e., the angle which a cutting edge encloses with the normal to the carrier surface, is larger than 45, a d by movplitudes of the vibrations to be recorded. 5

Thereby, as has been fully disclosed in said Patent 1,919,116, the vibration track reproduces the vibrations of the chisel with a considerable amplification.

In the vibration track so obtained, even the 10 high frequency vibrations have sufficiently large amplitudes and thus can be better recorded than by other known methods.

While cutting, the chisel removes portions of both the layer 2 and layer 3. The covering layer 15 3 merely serves to provide a difference in translucency between the track and the background so as to permit reproduction by means of light passing through the carrier. The covering layer 3 may consist of a very thin opaque layer of 20 paint, or dye, offering a practically negligible cutting resistance to the chisel.

Theactual cutting layer is layer 2, and the track can be cut into this layer before the covering layer is applied thereto, in which case an 5 opaque coating is applied either to the surface of the cut track or to the background at the sides of the track.

As stated before, the most suitable material for the layer 2 has been found to be gelatin. 30.

However, as appears from the left side of Figure 1, which shows, as viewed under a microscope,

a vibration track cut into such a layer, consisting, for instance, of ordinary gelatin, which has not been processed according to my invention, the 35 record shows a comparatively large number of scratches and a more or less coarse surface of at least part of the vibration track.

The scratches appear as longitudinal lines,

i. e., in lines extending in the direction of the 40 travel of the film.

Certain of these scratches, as indicated by the lines 5 of. Fig. 1, are due to the irregularities (indicated as 6 in Fig. 2) of the cutting edges of the chisel. 45

While even the best and newly sharpened cutting edges may show some irregularities, resulting in a limited number of unavoidable scratches, the effect of such scratches is practically negligible. 50

However, as has been stated before, with a gelatin layer not processed according to my invention, a rapid deterioration of the cutting edges takes place and the increasing irregularity of the. cutting edges causes a correspondingly in- 55 creasing number of scratches. At the same time -more power is required for the cutting, which causes heating up of the cutting edge and accelerates the deterioration of same.

As a result, after a comparatively short time, 60 the large number of scratches appearing on the vibration track, make the record unsuitable for high quality reproduction.

The scratches which appear at the borderlines of the track are especially detrimental, as the 65 borderlines determine the amplitudes of the recorded vibrations.

Furthermore, as stated, the adhesiveness or stickiness of the material of the cutting layer causes the adherence to the cutting edges of 70 particles ofthis material, such being indicated at 1 in Fig. 2. The number of such adhering particles also increases with increasing irregularity of the cutting edge. Such adhering particles also cause scratches, as indicated at 1A in Fig. 1,

which bring about further distortions in reproduction.-

The irregularities of the cutting edges may also show up as indentations or notches, as indicated by 8 in Fig. 2. These cause distortions in the record because at these notches the opaque covering layer will not be removed in accordance with the vibrations to be recorded. Suchindentations or notches of the chisel cause, in the vibration track, undesired opaque strips, as indicated in Fig. 1 by the strips 9, l0 and I I. Such unremoved strips, while representing the reverse of a scratch; because of their causing distortions similar to those caused by scratches, will be also referred to as scratches.

From the above it appears that because of the rapid deterioration of the tool, due to the comparatively poor cutting properties of the gelatin, as well as due to their adhesiveness to the tool, the number of scratches rapidly increases with the continued use of the tool and correspondingly decreases the quality of the record.

A further drawback of gelatin when used as cutting layers and also of other material used for this purpose-as has already been stated-is, that the surface of the vibration track, instead of being smooth, is rough, having a frosted appearance to the naked eye. If viewed under a microscope, the track surface appears more or less granular, as is indicated in the left side of Fig. 1.

The reason for the roughness or coarseness of the track surface, is because thecutting action of the chisel when cutting such unprocessed gelatin is far from ideal, in fact instead of having a pure cutting action, a chipping action takes place. In view of this, the cutting resistance of the material is considerably increased compared to the case in which a uniformly smooth track is cut;

this results in a rapid deterioration of the chisel,

a larger power consumption, and the heating up to the cutting edge of the chisel.

The frosted surface of the track has a further disadvantage, which manifests itself in the optical reproduction or photographic copying of the record for the following reasons:

As it is well known, a glass plate having a frosted surface passes less light than a similar glass plate having a smooth surface.- This is due to the fact that the surface of the frosted glass consists of a. large number of small individual sur faces, which forms with each other different angles and reflect the light in different directions. The same applies to the case of atransparent track having a frosted surface, the frosting causing a loss of light. Furthermore, such a frosted track, is not of homogeneous translucency, which results in background noises.

Diillculties also such a frosted track diffuses the passing light rays.

To obtain a good copy of. a vibration track of the a type discussed, parallel light rays are used in preference to diffused light rays, as in the case of diffused light the borderlines of the track do not appear with sufdcient sharpness, i. e., the

desired sharp contrast eifectis not obtained. However, when using a track having a frosted surface, as shown on the left side of Fig. 1, even when using a. light beam having parallel rays, the

rays are diffused in their pmage through the frosted surface of the track; thus the above draw- I backs of diffused light again appear.

All of the above difficulties are avoided or greatly reduced by processing the material of the cutting layer in accordance with my invention, 1. e.,

arise because 'of the fact that by treating the gelatin with a sulfonated castor oil.

The added substance may be mixed with the material of the cutting layer prior to the latter being made up into the carrier, or again it may -5 be applied to thislayer after it has been worked into a carrier.

Especially goodresults are found with a material obtained in the following manner: An aqueous solution of gelatin is first prepared by dissolving 10 6 to 10% by weight of gelatin in 100% by weight of water, at a temperature not exceeding 55 C. Thereafter 1 add to. 100 grams dry gelatin a quantity of at least 4 cubic centimeters, but preferably about 20 cubic centimeters of a sulfonated castor oil, preferably Tiirkonii The right side of Figure 1 shows a track made on a carrier according to the invention. As will be seen under the microscope, the vibration track has a smooth surface and exhibits only a very 20 small number of scratches, such as are due to irregularities present even on new and properly sharpened cutting edges, and the number of scratches does not increase materially even during a very long use of the same cutting tool with- '25 out resharpening.

Besides the smoothness of the track surface and the absence of scratches, my invention also insures a small wearing of the tool and a comparatively small power consumption.

While I have described my invention in a specific application, it can be applied generally in the mechanical recording of optically reproducible vibration tracks. Nor do 1. wish to be limited to the materials and substances described, 35 and the appended claims should be construed as broadly as permissible in view of the prior art.

What I claim'is:- I

1. In a carrier for the mechanical recording of sound-oscillations, a cutting layer containing gelatin and a sulphonated castor oil.

2. In a carrier for the mechanical recording of sound-oscillations, a cutting layer containing gelatin and polymerization-originated diricindisulfoacid.

3. In a carrier for the mechanical recording of sound-oscillations, a cutting layer containing gelatin and polymerization-originated diricindisulfoacid in the proportion of from 4 to 20 cubic centimeters of diricindisulfoacid to 100 grams of 50 dry gelatin.

4;. A composite carrier for the mechanical recording of sound-oscillations, comprising a transparent baselayer, a transparent cutting layer containing gelatin and a sulphonated castor oil, 55 and a thin opaque covering layer. I

5. In a carrier for the mechanical recording of sound-oscillations, a cutting layer containing gelatin and a sulphonated castor oil in the pro portion of from 4 to 20 cubic centimeters of sulphonated castor oil to 100 grams of dry gelatin.

6. A composite carrier for the mechanical recording of sound-oscillations, comprising a trans-' parent base layer, a transparent cutting layer containing gelatin and sulphonated castor oil in 55 the proportion of from 4 to 20 cubic centimeters of sulphonated castor oil to 100 grams of dry gelatin, and a thin opaque covering layer.

7. A composite carrier for the mechanical recording of sound-oscillations, comprising a transparent base layer, a transparent cutting layer, and a thin opaque covering layer, said cutting layer containing gelatin and p lym ri at onr nat d diricindisulfoacid in the proportion of from 4 to u 20 cubic centimeters of diricindisulicacid to 100 grams of dry gelatin.

8. A composite film for the mechanical recording of sound-osci11ations, comprising a transparent base layer, a transparent cutting layer containing gelatin and a sulphonated castor oil in the proportion of from 4 to 20 cubic centimeters of sulphonated castor oil to 100 grams of dry gelatin, and a thin opaque covering layer.

9. A composite film comprising a transparent base layer, a transparent cutting layer containing sulphonated castor oil and gelatin in the proportion of from 4 to 20 cubic centimeters of sulpnonated castor oil to 100 grams of dry gelatin, 9. thin opaque covering layer, and an optically and mechanically reproducible sound track on said film.

CORNEIJS J OHANNES DIPPEL. 

